Wind Turbine Provided With Yaw Brake

Abstract

A wind turbine comprises wind turbine blades extending substantially radially from a hub on a main shaft having a substantially horizontal axis. The blades together with the hub form a rotor, which can be put into rotation by wind. The main shaft is rotatable mounted in a nacelle on top of a tower, and the nacelle may be rotated around a vertical axis in relation to the tower to adjust the rotor in relation to a prevailing wind direction. The wind turbine further comprises a yaw brake comprising a brake calliper and a brake disc or ring having a first side with a first surface and second side with a second surface, the yaw brake, when activated, acting as a rotation restriction of the nacelle in relation to the tower. The brake disc or ring is provided with one or more grooves formed in the first and/or second surfaces.

1 . A wind turbine ( 2 ) comprising:
 a number of wind turbine blades ( 10 ) extending substantially radially from a hub ( 8 ) on a main shaft ( 15 ) having a substantially horizontal axis, the wind turbine blades ( 10 ) together with the hub ( 8 ) forming a rotor, which can be put into rotation by wind,   the main shaft ( 15 ) being rotatable mounted in a nacelle ( 6 ) that is mounted on top of a tower ( 4 ), wherein   the nacelle ( 6 ) may be rotated around a vertical axis ( 18 ) in relation to the tower ( 4 ) so as to adjust the rotor in relation to a prevailing wind direction, and wherein the wind turbine ( 2 ) further comprises   a yaw brake system ( 20 ) comprising a brake calliper ( 24 ) and a brake disc or ring ( 22 ) having a first side with a first surface and second side with a second surface, the yaw brake system ( 20 ), when activated, acting as a rotation restriction of the nacelle ( 6 ) in relation to the tower ( 4 ), wherein   the brake disc or ring ( 22 ) is provided with one or more grooves ( 30 ,  130 ,  230 ,  330 ,  430 ) formed in at least one of the first surface and the second surface.   
     
     
         2 . A wind turbine according to  claim 1 , wherein the one or more grooves are oriented so that they extend to a peripheral part of the brake disc or ring. 
     
     
         3 . A wind turbine according to  claim 1 , wherein the one or more grooves are oriented so that they extend in a substantially transverse direction compared to a brake pad ( 26 ) mounted on the brake calliper ( 24 ). 
     
     
         4 . A wind turbine according to  claim 1 , wherein the yaw brake system further includes at least a first brush comprising bristles, and which is arranged so as to contact the at least one of the first surface and the second surface of the brake disc or ring ( 22 ) for facilitating removal of dust from the one or more grooves ( 30 ,  130 ,  230 ,  330 ,  430 ) formed in the at least one of the first surface and the second surface. 
     
     
         5 . A wind turbine according to  claim 4 , wherein the first brush is oriented substantially along a radius of the brake disc or ring. 
     
     
         6 . A wind turbine according to  claim 4 , wherein the first brush has an end which is loosely supported or pivotally supported. 
     
     
         7 . (canceled) 
     
     
         8 . A wind turbine according to  claim 6 , wherein the yaw brake system is further provided with one or more stops for limiting an angular movement of the first brush. 
     
     
         9 . (canceled) 
     
     
         10 . A wind turbine according to any of  claim 4 , wherein the yaw brake system further comprises a second brush comprising bristles, and which is arranged so as to contact the at least one of the first surface and the second surface of the brake disc or ring ( 22 ) for facilitating removal of dust from the one or more grooves ( 30 ,  130 ,  230 ,  330 ,  430 ) formed in the at least one of the first surface and the second surface, wherein the first brush and the second brush are oriented convergently. 
     
     
         11 . (canceled) 
     
     
         12 . A wind turbine according to  claim 10 , wherein the first brush is oriented in a first, positive angle compared to a radius of the brake disc or ring, and wherein the second brush is oriented in a second, negative angle compared to the radius of the brake disc or ring. 
     
     
         13 . A wind turbine according to  claim 4 , wherein the first brush comprises a housing having a first surface from which the bristles extend, said first surface of said housing and said bristles facing towards the first surface and/or the second surface of the brake disc or ring, and wherein the housing comprises a first side, a second side, a first end, and a second end. 
     
     
         14 . A wind turbine according to  claim 13 , wherein the first side and the second side of the first brush are tapered in a direction towards a peripheral part of the brake disc or ring. 
     
     
         15 . A wind turbine according to  claim 4 , wherein the yaw brake system further comprises a first additional brush, wherein the first brush is arranged along a part of the first surface of the brake disc ring, and wherein the first additional brush is arranged along a part of the second surface of the brake disc or ring. 
     
     
         16 . A wind turbine according to  claim 15 , wherein the first brush and the first additional brush are arranged on a common base, which is arranged at a peripheral part of the brake disc or ring so that the first brush and the first additional brush straddle a part of the brake disc or ring. 
     
     
         17 . A wind turbine according to  claim 1 , wherein the one or more grooves are angled with respect to brake pads mounted on said brake calliper. 
     
     
         18 . (canceled) 
     
     
         19 . A wind turbine according to  claim 1 , wherein a cross-sectional area of the one or more grooves increases towards a periphery of the brake disc. 
     
     
         20 . A wind turbine according to  claim 1 , wherein the one or more grooves has a sidewall that is inclined near a top portion of the sidewall so that the top portion forms an acute angle to the first surface or the second surface of the brake disc. 
     
     
         21 . A wind turbine according to  claim 1 , wherein the one or more grooves have a sidewall that form a sharp edge at the at least one of the first surface and the second surface of the brake disc. 
     
     
         22 . A wind turbine according to  claim 1 , wherein the one or more grooves have an internal ridge within the one or more grooves. 
     
     
         23 . A wind turbine according to  claim 22 , wherein a cross-sectional area of the ridge is increasing towards a periphery of the brake disc. 
     
     
         24 - 26 . (canceled) 
     
     
         27 . A wind turbine according to  claim 1 , wherein the brake disc is provided with a plurality of grooves on the at least one of the first surface and the second surface of the brake disc. 
     
     
         28 . (canceled)